To achieve high density values in wires, it is known (U.S. Pat. No. 2,804,408) first to cold draw the wire, to soft anneal same and finally to cold draw it again. During the last cold drawing the cross section is reduced in brass and tombac wires 8 to 10% and in the case of bronze approximately 30%. This after deformation causes hardening, which is advantageous in many cases, thus particularly also when used as paper machine screen, with respect to the wear behavior and with respect to a good reverse bending strength.
According to previous manufacturing practice, the wire was wound after the first cold drawing, then slowly unwound and guided through an annealing furnace and again wound, and thereafter subjected to the second cold drawing. This method is very time consuming because of the many winding and unwinding operations and the necessarily slow passage through the annealing furnace. It is therefore also expensive. In addition, breakdowns occur easily, mainly in pulling off the wire from the spools during the last cold drawing operation. Finally, during this drawing operation only a small deformation of a thin wire takes place and such could actually take place at very high speeds of for example 40 m./sec. under circumstances where the unwinding operation can occur only at a maximum speed of 15 m./sec. Thus, the drawing operation is very uneconomic.